'use strict';

const fs = require('fs');
const path = require('path');
const Sequelize = require('sequelize');
const basename = path.basename(__filename);
const env = process.env.NODE_ENV || 'development';
const config = require(__dirname + '/../config/config.json')[env];
const db = {};
let sequelize;
if (config.use_env_variable) {
    sequelize = new Sequelize(process.env[config.use_env_variable], config);
} else {
    sequelize = new Sequelize(config.database, config.username, config.password, config);
}


fs
    .readdirSync(__dirname)
    //返回数组类型，文件下所有文件名
    .filter(file => {
        //file.indexOf()返回字符在file中的位置,filter是筛选器。排除不符合条件的文件名
        return (file.indexOf('.') !== 0) && (file !== basename) && (file.slice(-3) === '.js');
    })
    .forEach(file => {
        const model = require(path.join(__dirname, file))(sequelize, Sequelize.DataTypes);
        db[model.name] = model;
    });
//db = { Role: Role, User: User }
//modelName是对象的key值
Object.keys(db).forEach(modelName => {
    if (db[modelName].associate) {
        db[modelName].associate(db);
    }
});

db.sequelize = sequelize; //实例化后的对象
db.Sequelize = Sequelize; //顶级类

module.exports = db;